U.S. Pat. Nos. 4,023,037 and 4,118,099 corresponding to German Patent Application Nos. P 2414 322 and P 25 35 408 teach that an object can be coded by irradiating the object, for example, by means of X-rays from different positions which together form a point-image function, and to record the shadow images thus formed on one and the same film as a superposition image. In a decoding step, an object image is then decoded from the superposition image by correlation of the superposition image with the image point function. This not only produces the decoded object image, but also secondary images (so-called artifacts) which disturb the decoded object image.
The invention has for its object to provide a method of the kind set forth which enables a decoded object image to be obtained which does not include secondary images which disturb the decoded object image.